ESL, EFL, TESL, TEFL, TESOL, ESOL

What do ESL, EFL, TESL, TEFL, TELSOL, and ESOL mean? I've seen it a lot on this site, and I'm still not sure what exactly it means.

[Red5]

ESL = English as a Second Language
EFL = English as a Foreign Language
TESL = Teaching English as a Second Language
TEFL = Teaching English as a Foreign Language
TESOL = Teachers of (or Teaching) English to Speakers of Other Languages
ESOL = English for Speakers of Other Languages